[vp8 @ 0x7fbebd0bf000] Discarding interframe without a prior keyframe!
Error while decoding stream #0:0: Invalid data found when processing input


Original Script

ffmpeg -y -i ./435402179592964100.mkv -i ./58767b5d028f6066197d6be1-0.png -i ./58767b5d028f6066197d6be1-poster.png -filter_complex "[0:0]setsar=1/1,trim=start=201:duration=28,setpts=PTS-STARTPTS[v0fit];[v0fit] scale=640:480 [v0resized];[0:a]atrim=start=201:duration=28,asetpts=PTS-STARTPTS,aresample=44100,aformat=sample_fmts=s16:channel_layouts=stereo[a0resampled];[v0resized][1:v]overlay=x=0:y=0[vback1];[2:0]setsar=1/1,format=pix_fmts=yuv420p,trim=duration=0.04[vposter];[vback1][vposter]overlay=repeatlast=0[vconcat]" -map "[vconcat]" -map "[a0resampled]" -vcodec libx264 -b 2000k -acodec aac -preset ultrafast -strict -2 -movflags +faststart ./58767b5d028f6066197d6be1-0.mp4